| 摘要 |
<p>A symmetric procedure avoids the problems with prior art systems using modifiers with master keys and generates a secure session key from a secret master key and an additional pair of randomly selected signals. The secret master key is known to both parties: one at station A and one at station B. One randomly selected signal of the pair is generated by the party at station A while the other signal in the pair is generated by the party at station B. In one embodiment, a random number signal sent by each one of the parties to the other is encrypted before transmission and decrypted upon reception. Both encryption (at one station) and decryption (at the other station) employ symmetric key cryptographic systems which use the secret master key. The session key is then formed by a commutative combination of both random number signals. <IMAGE></p> |
